Carburetor



Oct. 30, 1934. A. III. KING 1,978,429

CARBURETOR Filed Nov. 29, 1930 2 Sheets-Sheet l mmnon A TTORNEY Oct. 30, 1934. v A. H. KING 1,978,429

CARBURETOR Filed Nov. 29, 1950 2 Sheets Sheec 2 INVEN TOR Kim/C;

AT URI/EV Patented Oct. 30, 1934 PATENT OFFICE CAR-BURETOR Alexander ll. King, West Hartford, Conn., assignor to The Pratt & Whitney Aircraft Com- Dany, East Hartford, Delaware Gonn a corporation of Application November 29, 1930, Serial No. 499,011

7 Claims.

This invention relates to-internal combustion engines and in particular to means for regulating the quantity and richness of the fuel supply therefor.

An object of the present invention is to provide means controlling the richness of fuel mixtures for internal combustion engines enabling an operator to readily control the fuel mixture for uniform and efficient operation of the engine at different atmospheric pressures.

A feature of importance of the invention is the provision of a manual control lever supplemental to the throttle controlling lever which may be adjusted during operation to limit the amount of liquid fuel admitted to an engine at different throttle openings.

Another object of the invention is the provision of a supplemental manually operated lever connected to the throttle controlling means and infiuencing the fuel admission so that with the supplemental lever in different positions the fuel admitting means will be opened to different degrees by the same movement of the throttle lever.

Another feature of advantage is that the ratio of opening movement of the fuel admitting means may be widely varied relative to the opening movement of the throttle valve controlling the admission of air; that is, the position of the fuel admitting means may be widely varied for any predetermined position of the throttle valve, this being accomplished by setting a supplemental leverassociated with the throttle lever.

And finally it is an object to provide a simple control mechanism for aircraft engines enabling the operator to vary the fuel admitted to the engine to maintain the fuel and air mixture at any desired and efficient ratio under widely varying atmospheric pressures by a simple lever in addition to that for the throttle.

With the above and other objects in view, my invention includes the features of construction and operation set forth in the following specification and illustrated in the accompanying drawings. r

In the accompanying drawings annexed hereto and forming a part of this specification, I have shown my invention embodied in a form adapted for internal combustion engines respectively of the carburetor type, but it will be understood that the invention can be otherwise embodied and that the drawings are not to be construed as defining or limiting the scope of the invention, the claims appended to this specification being relied upon for that purpose.

In the drawings:

Figure 1 is a diagrammatic view, partly in'section, showing the intake and carburetor of an internal combustion engine to which the present invention is applied.

Fig. 2 is a view of the linkage actuated by the manually operated arms for controlling the throttle opening and fuel admitting means, the linkage being shown in open and closed positions.

Fig. 3 is a view similar to Fig. 2 but showing the throttle operating lever in its closed position only, the supplemental lever being shown in its two extreme positions; and

Fig. 4, is an end view of the linkage shown in Fig. 3.

In the above mentioned drawings I have shown an embodiment of the invention which is now deemed preferable and as applied to a type of internal combustion engines for aircraft, but it is to be understood that changes and modifications may be made within the scope of the appended claims without departing from the spirit of the invention.

In the operation of internal combustion engines as applied particularly to aircraft, it is desirable to provide controlling means for the fuel admission so that while flying at varying altitudes the amount of fuel may be adjusted readily for the particular atmospheric pressure within which the engine is being operated. With an engine operating substantially at sea level, where the atmospheric pressure is relatively high, the amount of air passing into the intake of an engine with a given throttle opening is far greater than with the same throttle opening at an ex-' tremely high altitude and greatly reduced atmospheric pressure. It will be apparent, therefore, that with the same amount of fuel being admitted to the intake with the same throttle opening at high elevations as at sea level, the mixture at higher altitudes will-be much richer. It is therefore a principal feature of the invention to provide simple manually operated means which may be adjusted readily for flying at different altitudes with the richness of the mixture maintained substantially uniform at all throttle openings. The mixture controlling mechanism illustrated in the drawings is operated directly from and is mounted upon a throttle opening lever so that in one position of the supplemental lever movement of the throttle valve by its lever will open the fuel admitting means at one rate while in another position of the supplemental lever the fuel opening will be more slowly opened while moving thethrottle lever to its full open position.

Referring more in detail to the figures of the drawings, I show in Fig. 1 an intake 10 for an internal combustion engine having the ,usual form of butterfly valve 11 therein which may be opened and closed by an arm 12 reaching to the cockpit or other point of operation of the engine. This valve 11 and its operating means may be similar to the throttle controlling mechanism of a standard internal combustion engine. The valve 11 is mounted fixedly on a transverse shaft 13 extending through the intake 10 and having an operating lever 14 on its outer ends The reach rod 12 is attached at the free end of this lever 14 and may be operated axially in the usual manner by any convenient manual means (not shown) to effect opening and closing of the valve 11.

Adapted to be actuated by movement of this throttle lever 14 is a lever 15 pivotally mounted upon an intermediate point thereof, as shown at 16. One end of this pivotally mounted lever 15 is connected through a reach arm 17 and other connections to a needle or other form of valve 18 controlling the amount of fluid admitted to the throat 19 of a carburetor through an orifice 20. These parts are shown diagrammatically in Fig. 1. The lever 15 pivotally mounted on the throttle lever 14 is extended beyond its point of attachment to the throttle lever 14 and is provided upon this end with an arcuate slot 21. Engaging this slot 21 is a pin 22 upon one arm of a bell crank 23, the bell crank being supported for oscillatory movement about a suitable fixed axis. The opposite arm of this bell crank has a reach arm 24 extending to any convenient means arlever 14.

ranged for operation from the cockpit.

With the bell crank 23 in the position shown in full lines in Fig. 3, the pin 22 engaging the arcuate slot 21 in the lever 15 is directly in alinement with the shaft 13 carrying the butterfly valve 11 so that movement of the lever 14 from closed to open position moves the lever 15 pivoted upon the throttle lever from one limiting position to its opposite extreme limiting position, the open position being indicated in full lines in Fig. 1. In this position of the bell crank 23 and reach arm 24 the pin 22 has no modifying effect upon the opening movement of lever 15. The fuel admitting valve 18 shown diagrammatically as a needle valve admitting liquid fuel to a carburetor is therefore opened to its maximum open position by this movement of lever 14 with the bell crank 23 in the position shown in Fig. 3.

Oscillation of the bell crank 23 by means of its reach arm 24 moves the pin 22 outof alinement from the axis of the shaft 13 carrying the butterfly valve 11. Movement of the throttle lever or arm 14 in any such position of the pin 22 modifies movement -of the supplemental or pivoted lever 16 controlling the fuel admitting means 18 relative to the movement of the throttle As the pivoted lever 15 is oscillated about its pivot 16 upon thethrottle lever 14 by opening movement of the throttle lever 14, the

opening movement of the lever 15 will be somewhat reduced. With the throttle lever 14 moved to its maximum open position and with the pin 22 in the position shown in full lines in Fig. 2, the effect of the arcuate slot 21 causes the lever 15 to be moved only to the full line position in Fig. 2. In this position of the lever 15 the fuel admitting means 18 is moved by its reach arm 1'! to a partial opening only.

In operation while operating at substantially sea level, the bell crank 23 would be adjusted by its reach arm 24 so that the pin 22 is substantially in alinement with the shaft 13 supporting the butterfly valve 11. This position of the pin 22 is shown in Fig. 3. Movement, therefore, of the throttle valve 11 by its lever 14 and reach arm 12 will give the fuel valve 18 its maximum opening movement. With the pin 22 moved to the position substantially as shown in full lines in Fig. 2, opening movement of the fuel valve 18 will be limited by reducing the movement of the pivoted lever 15 while the throttle lever 14 is being moved toward its full open position. With the bell crank 23 moved to intermediate positions the effect of the engagement of the pin 22 with the slot 21 upon the pivoted lever 15 is to proportionately vary its ratio of opening movement to the opening movement of the valve 11 by lever 14. By adjusting the position of the bell crank 23 from that shown in Fig. 3 to that shown in Fig. 2, the fuel admission may be regulated to maintain a substantially uniform mixture at any atmospheric pressure.

What I claim is:

1. A carburetor for internal combustion engines comprising in combination, a throttle controlling mixture outlet of the carburetor, means controlling admission of fuel, a lever controlling said throttle, a second lever pivotally mounted on said first lever controlling said fuel admitting means, and supplemental means controlling the pivotal movement of said fuel controlling lever relative to said throttle controlling lever, said supplemental means being'adjustable during operation of the engine.

2. A carburetor for internal combustion engines comprising in combination, a throttle controlling the mixture outlet of the carburetor, means controlling admission of fuel, a lever controlling said throttle, a second lever controlling said fuel admitting means, and a manually operated supplemental lever engaging said second lever for varying the amount of opening of said fuel admitting means for different positions of said throttle.

3. A carburetor for internal combustion engines comprisingjn combination, a throttle controlling the mixture outlet of the carburetor, means controlling admission of fuel, levers operating said admitting means, one lever being pivotally mounted upon the other, cam means varying the movement of said pivoted lever for different movements of said first lever, and manual means controlling the position and effect of said cam means upon said pivoted lever whereby the positions of said levers relative to each other may be varied for different throttle openings.

4. A carburetor for internal combustion engines comprising in combination, a throttle controlling the mixture outlet of the carburetor, means controlling admission of fuel, levers respectively operating said admitting means, one lever being pivotally mounted upon the other at an intermediate point thereof, cam means varying the movement of said pivoted lever relative to the first lever for different movements of said first lever, and manual means controlling the position and effect of said cam means upon said pivoted lever. I

5. A carburetor for internal combustion engines comprising in combination, a throttle controlling the mixture outlet of the carburetor, means controlling admission of fuel, interconnected levers respectively operating said admitting means, one lever being pivotally mounted upon the other at an intermediate point thereof, cam means acting upon an extension of said pivoted lever for varying the movement of said pivoted lever for different movements of said first lever, and manual means controlling the position and eflect of said cam means upon said pivoted lever.

6. A carburetor for internal combustion engines comprising in combination, a throttle valve controlling the mixture outlet of the carburetor, a lever for manually opening and closing said valve, a fuel admitting valve, operating means therefor controlled by movement of said throttle valve lever to simultaneously open and close said fuel admitting valve with said throttle valve, and a supplemental manually operated lever movement of which varies the amount oi openings of the fuel admitting valve for predetermined openings of said throttle valve, said supplemental lever being adjustable during operation of the engine.

7. A carburetor for internal combustion engines comprising in combination, a. throttle valve controlling the mlxture outlet of the carburetor, a lever for manually. opening and closing said valve, fuel admitting means, operating means therefor controlled-by movement of said throttle valve lever to simultaneously open and close said fuel admitting means with said throttle valve, cam means engaging the'operating means for said fuel admitting means; and a manually operated lever for adjusting saidcam means whereby the amount of opening of said fuel admitting means may be varied 'ior predetermined throttle valve 

